The Public Administration Select Committee of MPs will take evidence from charity bosses during an investigation into what Bernard Jenkin, the committee's chair, said were "vile and disgusting" fundraising techniques.
Speaking on ITV's Good Morning Britain programme, Jenkin, a Conservative, said: "There's no question that we will be doing an inquiry into this in the autumn." He said charities were in the "last-chance saloon".
Jenkin said that his committee had picked up concerns about charity cold-calling in 2013, but had not looked into them fully.
"We're very, very disappointed that this is still going on," he said, and unless the sector acted and created a "serious self-regulatory body" the government "will have to bring forward legislation".
He said the government might wait for the PASC, but ministers "may well choose to act on their own volition".